MBA keyboard is dicey & wants to power down

2012 Macbook Air 13" had water dumped into it. It's been about a month and a half now so I think all water has dried out by now.

It boots up, wifi works, charges great, but the keyboard mostly only works on the left side. External keyboard works just fine. The main issue is that a message keeps coming up on screen asking if I'm sure I want to shut down. I can cancel and it stays alive but the message often comes back. Closing the lid always causes a shutdown.

I'm willing and (hopefully) able to replace the upper case assembly (sounds like fun actually). Does it stand to reason that this would be likely to fix the problem I'm having? If so I think I'll do it!

Oh, and my plan is to see if I can find something sticky/corroded to clean first in the power switch once I get in there to save $200.